DIAGNOSIS Chuck wobble indicates a manufacturing defect or damage. The chuck is not seated perfectly perpendicular to the spindle, or the spindle itself is bent.
FIX Test with a known-true drill bit. Install a new, high-quality bit and tighten the chuck fully. Observe the bit tip while running the drill at low speed with no load. Visible wobble at the bit tip confirms the issue. For a new tool, this is a warranty claim.
IF THAT DIDN'T WORK If the bit doesn't wobble but the chuck body does, the chuck is defective. The 2904-20 uses a Rohm chuck. It can be replaced, but misalignment could also be in the spindle taper. A service center can determine the root cause.
HEADS UP Using a drill with a wobbly chuck accelerates wear on the gearbox bearings and produces inaccurate, oversized holes. Address it immediately.